The trigonometric circle or unit circle is a circle with a radius of one unit; it is widely used in mathematics, especially in trigonometry. Students confront lots of difficulties in understanding how the trigonometric circle works, and what can be done with this circle for the following reasons:
1 . The trigonometric circle has a rotating radius, and it is very difficult to imagine something that rotates by only drawing it on papers and relying on students' imagination.
2 . To draw a trigonometric circle, one needs to have a paper, a ruler, a pencil, a set square, a compass, and a protractor; the later procedure will waste the students' time.
3 . Most of the students confront difficulties in understanding of basic trigonometric relationships between the sine and cosine of angles, especially those illustrated in FIG. 1.
Moreover, trigonometric functions are widely used in carpentry, whether in cuts, or to calculate the dimensions of windows, or for sloped roofs calculations, etc. Carpenters, however, don't know about trigonometric functions and their applications: indeed, carpenters need easy measurement tools, which enable them to find the required measurements with the minimal calculation effort. The common used instruments in carpentry are the layout square and the steel square; the layout square is very helpful in determining angles (similar to any protractor), and the steel square helps in determining slopes and cuts; however, the carpenter still needs to perform some calculations based on the rafter table found on the steel square itself. In addition, using large amount of instruments increases the complexity of the carpentry process, and most of the carpenters seek to have the minimal possible amount of such measurement tools.
The New Trigonometer is invented to address and solve the above point of pains for students and carpenters; thus, its usefulness doesn't rely in its capability to find the trigonometric functions, but instead by its application in places where the use of scientific calculators discerns to be useless: in education, when students are first taught about trigonometry, and in carpentry, where most of the carpenters don't know about trigonometry.
The New Trigonometer falls under the category of utility patent, as defined by the recent issue of PTU patent because it is a new and useful invention, and its usefulness is justified by its capability of addressing the above points of pain for students and carpenters.